书城教材教辅科学读本(英文原版)(套装1-6册)
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第150章 第二册(67)

"Now, I think, perhaps I can tell you something you do not know about your rabbit," Fred added. "To begin with, if you look at the top lip, you will see that there is a cleft up themiddle, which divides it into two halves. As it moves the lips, you can see the four front teeth, two in the upper jaw and two in the lower. They are long, broad,and flat, and very sharp at their edges. Teacher calls them chisel teeth. You have seen father cut off pieces of wood in slices with his chisel.

"Let us give Bunny this carrot, and watch how it eats. See, it gnaws or nibbles off pieces with itsfront chisel teeth. The rabbit is called a gnawing animal because it eats like this. The top lip is split to help it in its gnawing.""Look, Fred," said Willie, "the lower jaw moves from side to side, as well as up and down, while the rabbit is eating.""Then I suppose," said Norah, "the other teeth in both jaws are grinders, for chewing or grinding up the food.""Now I want you to look at the feet," said Fred. "The front legs are shorter than the hind ones. Rabbits move very quickly, but instead of running like most animals, they leap or jump about on their strong hind legs.